1602 LCD Minimum Wires?

[rg12]

I was told I can go with only 9 wires connected to the LCD's 16 pin connector and have it work WITH backlight but it doesn't.
I have this arduino device and it works with a minimum of 11 (had to connect pin 15 and 16 to get the backlight on).
It seems that I have ground on 3 of the pins on the device side but disconnecting any of them would make the LCD not work properly.
Any idea what I'm doing wrong?

 

[rg12]

Anyone?

 

[dustNbone]

I remember setting one of these up with a Pi, and IIRC I had to put a resistor across the "Contrast" pads to get it visible. It seemed to be displaying things but they were too dim to be visible.

Also you might need to bridge the ground pins on the LCD module, they're all grounds but they seem to ground different things.

 

[rg12]

I remember setting one of these up with a Pi, and IIRC I had to put a resistor across the "Contrast" pads to get it visible. It seemed to be displaying things but they were too dim to be visible.

Also you might need to bridge the ground pins on the LCD module, they're all grounds but they seem to ground different things.

Thanks alot!
and yeah, I have a variable resistor on the main board to calibrate the lcd contrast